pcmhacking.net

I apoligise if this is already on here somewhere but I can not find the answer anywhere and it's doing my head in.....

VR V8 auto. Basic cam, intake, heads decked etc etc. Tuned and running well.

Pulled motor out for just a basic freshen up, noticed when pulled the plugs out a couple of the injectors were leaking.

Motor is nearly ready to go back in and I have a set of 775 injectors sitting around I may as well use.

I'm using tunercat rt software and a moates emulator.

My BPC is currently set at 158 for standard injectors, How do I work out the number to put in here or what area of the tune do I need to change?

Any help appreciated.

this should help

http://pcmhacking.net/forums/viewtopic.php?f=3&t=334

Thanks mate.

Had a play around this morning and not sure if it worked correctly. Spread sheet said there was an error every time I loaded it.

Anyhow my result from what I understand.

775 = lb/h 18.5

4.9/8 0.6125

BPC = 0.131

If this is correct then in my tune does that mean I change the 158 to 131?

from what i can see of 775's they are 27lb ?

if that's the case its going to be more like .096

I thought they were 24lb lol. This is where I got the 18.5 from http://www.fuelinjector.citymaker.com/F ... Rates.html

I just re-entered the figures at 27lb and come up with 0.090.

That could be something to do with the error when opening the spreadsheet maybe

that may be right, are they the magna blue top ones ?

whats the error with the spreadsheet ?

775 blue tops? They are 24lb IIRC?

The XDF your using is not using any sort of calc if the value is 158 (this is 0.1466 in KINJFLOW terms). The numbers in the kinjflow spreadsheet are going to be very different.

An easy way for various changes is this..
(New Disp/ Old Disp) * Current KINJFLOW = New KINJFLOW
(Old Inj/ New Inj) * Current KINJFLOW = New KINJFLOW

The only one thats not a linear change is if you change fuel pressure...
Square root of (new pressure/old pressure) * Current KINJFLOW = New KINJFLOW

Just googled and they are 24lb. I purchased them as HSV injectors a couple years ago.

ERROR----
Problem with formula M17
The formula is too long or complex, or contains a formula that is not supported

When you continue and the spread sheet opens is says that one error was found.

I'm only running the trial version of microsoft works cause I very rarely use it, maybe it's limited in the trial version.

Sorry mate, what you just wrote above made no sense to me as to how to convert the result to a number to use as the cat tuner BPC

Use .. 19/24 * 158 = 125

Put 125 in place of 158 in TC.

19/24 is old injector lb/new injector lb * current BPC ?

Sorry for the questions just trying to understand the theory side of what i'm doing for future injector changes